Google co-founder and Chief Executive Larry Page's wedding this weekend is supposed to be a secret affair. But his own search engine is undermining the effort. A recent Google search for "Larry Page marriage" revealed a number of details about the event. Page will definitely be married on Dec. 8 to a woman named Lucy Southworth at an "undisclosed location." According to one blog post, Page might be married on Necker Island, Richard Branson's 74-acre estate in the British Virgin Islands.

In this Web-friendly age, billionaires, politicians, and others who live in the public eye have a hard time keeping information about their lives private. Because the public is so interested in the marriages of the rich and famous, every detail of a billionaire's personal life — from courtship to wedding to, if they're unlucky, divorce — ends up shooting through millions of fused networks and popping up on millions of strangers' computer screens. It's true if you're Bill Gates of Microsoft, Warren Buffett of Berkshire Hathaway, or Oprah Winfrey of Harpo Entertainment. Page is no exception.

Yes, the rich really are different from you and me. For most people, a wedding is a simple, joyous occasion. Family and friends gather to celebrate the ceremonial joining of you and your true love. For billionaires it's more complicated, with stresses and strains that others don't bear. They don't just have to choose a florist and a band; they usually need a good lawyer, too.

Attorneys familiar with billionaire marriages urge their clients to proceed with care and caution. "A billionaire has to treat an upcoming marriage as a merger. But it's a merger with a potential enemy," says New York divorce lawyer Raoul Felder.

Prenuptial agreements are important, but they're no guarantee of a satisfactory split if things go south. Consider the divorce of Steven Spielberg, now at DreamWorks Animation, and his first wife Amy Irving. She claimed their prenup was invalid because it had been written on a napkin and she hadn't had legal representation. A judge tossed it out; Irving got $100 million.

The prenup of Bob Johnson, the founder of Black Entertainment Television, held up, but it still cost him plenty. He agreed to a deal with his wife, Sheila Johnson, in which she would receive half of their assets if they split up. By the time they did get divorced in 2002, his media empire was worth billions — and she got her half. "Very rich people have trouble sometimes knowing exactly what they're worth," says Felder. "Worth is often ephemeral."

Valuations are tricky, too. Donald Schiller, of Chicago's Schiller, Du Canto & Fleck, the nation's largest matrimonial law firm, says valuing a billionaire's worth is particularly complicated when real estate and other privately held property is involved. "You can't evaluate them the same way you can evaluate assets traded on the New York Stock Exchange," he says.

Dishing dirt
Another issue that comes with prenups is privacy. Agreements can include confidentiality clauses to prevent one of the parties involved from giving out information about a marriage in case of divorce. That can mean barring anything from TV interviews about the ex to writing a book. "Prenuptials often waive a spouse's rights to develop intellectual property from details of the marriage," says Schiller.

He continued, "If it's a well-done premarital agreement and well-documented, the person trying to get out of it could end up with a lot less [if he or she goes public]," Schiller says. "You have to make it…very expensive…for somebody to give a lot of personal information out to the public."

Friendly divorces are rare

It's possible to have an amicable divorce, even if you're a billionaire. When Tim Blixseth, the billionaire founder of the Yellowstone Club, split from his wife, Edra, in 2006, they divided up $2 billion in combined net worth in a single afternoon.

But that is the exception. You're more likely to see a high-profile mudfest like the one Roman Abramovitch, the Russian oil magnate, got into in March, 2007. His wife, Irina, learned that Roman was dating a 23-year-old Russian model, Daria Zhukova. Irina hired two prominent British lawyers, filed for divorce, and ended up with half of her husband's assets.

Given all of the billionaire marriages that have ended badly, Larry Page may well have a prenup ready before he takes his vows on Dec. 8. Money doesn't buy happiness, even if you're capable of spending billions.

Still, Page could give up half his wealth and still be plenty rich. With Google's stock trading near $700, his stake in the search engine is worth nearly $20 billion.